A Primer on Google Ads Offline Conversion Import

Today’s post is written by Guest Author, Mike Nelson – Co Founder of Four15 Digital. We’re excited to share insights and guidance from additional industry voices here on the Clix blog, so make sure you stay tuned to the Guest Post category!

Of late, you’ve surely observed a lot of changes with cookies and privacy. Changes like we saw with iOS 14 are here to stay, and the marketing world has been talking about a ‘cookieless’ ecosystem for over a decade (really, it’s a march towards an ecosystem that depends only on 1st party cookies). So, rather than wait around for these cookie shenanigans to continue to unfold, it’s better to move over to a different data architecture entirely. 

As a marketer, it’s now more important than ever to make sure the information that Google, Facebook and Microsoft have is accurate. This means it’s not inflated, deflated, duplicated, or any other common data faux paus. If you can accomplish this, machine learning (or “smart) bidding can do a much better job of hitting your actual goals, rather than optimizing towards something superfluous or of lower value. All of this is to say, it’s all about avoiding ‘garbage in, garbage out!’

Examples of optimizing to the right things include: 

  • Optimizing to qualified leads rather than raw leads
  • Optimizing to new buyers rather than any buyer
  • Optimizing leads based on company size restrictions rather than any size company


To do the above, you’ll need to come up with a map of different events to track, and different objectives for different campaigns, but that’s for another blog! For now, let’s focus on the method of getting offline conversion import live. 

Google has a great method of helping get your first party data into Google’s ecosystem. This is called ‘offline conversion import’. Offline conversion import is not based on any Google cookies whatsoever, but rather advertisers extracting the information from their database and formatting conversion data in a friendly sheet. 

Setting this up is more simple than you might think. There are basically two different templates. 

To use native Google attribution settings, use this template


To create your own attribution models, use this template 


The files can be delivered via FTP, Sheets or a few other methods. 

The most important callouts about offline import are below.

  • You must understand the GCLID
    • The GCLID is a huge string of numbers and letters that Google sets on every paid click. This string contains information about the user’s device, keyword, query, etc. Basically, all the information that the machines would need to evaluate later for optimization. Using the offline import and GCLID means there is absolutely no loss in reporting between cookie-based tracking (like to Google Ads tag or Google Analytics events) and offline tracking. This being said, you can not necessarily get all this information from the Google API. Only Google stores all of this information!
    • The GCLID is available in your user’s URL as long as you have auto-tagging enabled. By default, accounts have auto-tagging enabled.

  • Storing the GCLID and following the user’s downstream events is the job of your dev team or 3rd party software, not Google (though Google Tag Manager can store it!)
    • The name of this method of import is ‘offline conversion import’. This means it’s meant to track offline events (such as a phone call event), but I’d recommend tracking all events – whether offline or online, via offline conversion import. Now, I’m not a developer, but what we need to do is basically store the GCLID somewhere and associate the events that the user takes in the future (up to 90 days) to that original GCLID. An example of this is below. In short, this answers the question like this “For the GCLID that drove my registrations, what other events did the user take over the next 90 days?”
    • I don’t find nearly as much value in storing different GCLIDs for different events. For example, if the user took 3 different actions, I’d want to associate those all back to the original GCLID until that date range expires. Another option is to store a new GCLID every time you see one from that user, but it’s your decision.

As marketers, I’m not fully convinced that we all love our developers. If so, have no fear! There are tons and tons of tools that have automated offline conversion import for us so we don’t have to!

Here are a few examples


About 60% of our existing clients are opted into offline imports, but of course our goal is to get to 100% in due time. 

Be warned, offline import is only good for tracking clicks (the method depends on click IDs, and Google does not let you access impression beacons) so it’s not a great method for tracking performance of YouTube ads or anything where you want to understand impression or view value. Learn a bit more about that here. So, based on your campaign’s goals and objectives, you’ll likely be using a mixture of tracking data sources.